- A white solid K was heated. It produced a brown gas A and another gas B which relights a
glowing splint. The residue left was yellow...(Solved)
A white solid K was heated. It produced a brown gas A and another gas B which relights a
glowing splint. The residue left was yellow even after cooling.
a) Identify gases A and B
b) Write a balanced chemical equation for the decomposition of solid K.
Date posted: May 16, 2019. Answers (1)
- Below is a set up used to collect hydrogen gas.(Solved)
Below is a set up used to collect hydrogen gas.
a) Identify with reasons, two mistakes in the set up.
b) Explain the role of hydrogen in the manufacture of margarine.
Date posted: May 16, 2019. Answers (1)
- Complete the following reactions.(Solved)
Complete the following reactions.
Date posted: May 16, 2019. Answers (1)
- The scheme below shows some reaction sequence starting with solid M(Solved)
The scheme below shows some reaction sequence starting with solid M
(i) Name Solid M
(ii) Write the formula of complex ion present in Solution Q
(iii) Write ionic equation of reaction between barium nitrate and solution N.
Date posted: May 16, 2019. Answers (1)
- What is the oxidation number of chlorine in ClO-4?(Solved)
What is the oxidation number of chlorine in ClO-4?
Date posted: May 16, 2019. Answers (1)
- Identify the acid and base in the equation below.(Solved)
Identify the acid and base in the equation below.
Date posted: May 16, 2019. Answers (1)
- In terms of structure and bonding explain why diamond has a high melting point while
graphite has a low melting point.(Solved)
In terms of structure and bonding explain why diamond has a high melting point while
graphite has a low melting point.
Date posted: May 16, 2019. Answers (1)
- A compound G reacts with 2 moles of bromine to form another compound whose graphical
formula is.(Solved)
A compound G reacts with 2 moles of bromine to form another compound whose graphical
formula is.
i) What is the formula and name of compound G
ii) State the observations made when acidified potassium chromate (VI) is
added to compoundG
Date posted: May 16, 2019. Answers (1)
- Explain why the compound Cl2O has a very low melting and boiling point.(Solved)
Explain why the compound Cl2O has a very low melting and boiling point.
Date posted: May 16, 2019. Answers (1)
- Two elements A and B have electronic configurations 2.8.3 and 2.6 respectively.(Solved)
Two elements A and B have electronic configurations 2.8.3 and 2.6 respectively.
a) To which group and period does element B belong?
b) If the two react, what is the formula of the compound they form
Date posted: May 16, 2019. Answers (1)
- The graph below shows the decay for a sample of 400g of iodine -131. Study is and
answer question that follow.(Solved)
The graph below shows the decay for a sample of 400g of iodine -131. Study is and
answer question that follow.
(i) Use the graph to determine the half-life of the sample
(ii) What fraction of the original sample remains after 16.2 days.
Date posted: May 16, 2019. Answers (1)
- Define the following terms(Solved)
Define the following terms
(i) Nuclear fission
(ii) Nuclear fussion.
Date posted: May 16, 2019. Answers (1)
- The scheme below represents some reaction involving hydrocarbons. Study it and
answer the questions that follow.(Solved)
The scheme below represents some reaction involving hydrocarbons. Study it and
answer the questions that follow.
(i) Name Compound P.
(ii) Draw the structural formula of P.
(iii) Name the reagent and type of reaction taking place in process R.
(iv) What is a polymer.
(v) Identify the reagent used in Step 1
Date posted: May 16, 2019. Answers (1)
- Write an equation of reaction between ethene and chlorine gas and name the
product.(Solved)
Write an equation of reaction between ethene and chlorine gas and name the
product.
Date posted: May 16, 2019. Answers (1)
- Name the following compounds.(Solved)
Name the following compounds.
Date posted: May 16, 2019. Answers (1)
- Lead (II) ions react with iodide ions according to the equation(Solved)
(i) Lead (II) ions react with iodide ions according to the equation
300cm3 of 0.1M solution of iodide ions was added to a solution containing Lead (II)
ions. Calculate the mass of Lead (II) iodide formed (Pb= 207, I = 127).
(ii) Identify the colour of the product formed after the reaction above.
Date posted: May 16, 2019. Answers (1)
- (i) State and explain what is observed when ammonia solution is gradually added to a solution of Lead (II) nitrate until the alkali (ammonia) is...(Solved)
(i) State and explain what is observed when ammonia solution is gradually added to a solution of Lead (II) nitrate until the alkali (ammonia) is in excess.
(ii) Write an equation for the reaction that takes place in (i) above
Date posted: May 16, 2019. Answers (1)
- When Lead (II) nitrate crystals is heated strongly the crystals crackle and split because
of the gas accumulating inside.(Solved)
When Lead (II) nitrate crystals is heated strongly the crystals crackle and split because
of the gas accumulating inside.
(i) State three other observations that are made.
(ii) Write an equation for the reaction that takes place when Lead (II) nitrate is
strongly heated.
Date posted: May 16, 2019. Answers (1)
- (i) Describe how Lead(II) nitrate is prepared in the Laboratory starting from Lead (II) Oxide.
(ii) Write an equation for the reaction that takes place in...(Solved)
(i) Describe how Lead(II) nitrate is prepared in the Laboratory starting from Lead (II) Oxide.
(ii) Write an equation for the reaction that takes place in (i) above
Date posted: May 16, 2019. Answers (1)
- Explain the following. When concentrated sulphulric acid is added to copper turnings and the mixture heated, a reaction takes places producing a blue solution as...(Solved)
Explain the following. When concentrated sulphulric acid is added to copper turnings and the mixture heated, a reaction takes places producing a blue solution as one of the products, but when dilute sulphuric acid is added to copper turnings there is no charge even after heating.
Date posted: May 16, 2019. Answers (1)